HYDROPHOBICITY AND SERUM SENSITIVITY OF KLEBSIELLA-PNEUMONIAE TREATEDWITH SUB-MICS OF QUINOLONES

Cell surface hydrophobicity and serum sensitivity of Kiebsiella pneumo niae, after treatment with sub-minimum inhibitory concentrations (sub- MICs) of ciprofloxacin, norfloxacin and enoxacin, were studied. The qu inolones tested at 1/4, 1/8 and 1/16 of the MICs decreased surface hyd rophobicity. The most significant reduction of the bacterial cell surf ace hydrophobicity was found after treatment with antibiotics at 1/16 of the MICs (to 20.3% for both ciprofloxacin and norfloxacin, and to 2 3.6% for enoxacin, compared with control values). The most significant increase in the susceptibility of the bacteria to serum bactericidal activity was seen after 180 min incubation with ciprofloxacin and enox acin at 1/16 of their MICs. Survival of treated bacteria was 55 +/- 8% or 56 +/- 10% as compared with controls without antibiotics.